Iphone Spyware/Malware

I think I have some kind of virus that monitors everything I do, I don't have any unknown apps on my phone, I read another thread/topic about spyware, and it says that the only way your Iphone can have spyware is if another person is on the phone for 30 minutes, I have such a case, but I watched him and now he is acting kind of weird, he was digging into my settings because I had a problem with my Apple Store account but it's fixed now, I need answers, can someone install spyware on an Iphone and how can I actually know if my iphone really has a spyware, I'm struggling with this for 3 months, please someone help me. I'd really appreciate it!!